id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
23761	Mysql validator crashes with None db_type return. - Backport of master fix to 1.7	Adam DePue	Tim Graham	"When implementing a custom field type with a db_type() method that returns None, on Django 1.6 and below we would signify not to create a column at all.
With Django 1.7, this causes a crash with the mysql backend.
The issue is already fixed in master and this simply backports the safety check.

A fix was made in August in master:
https://github.com/django/django/commit/e9103402c0fa873aea58a6a11dba510cd308cb84#diff-14

The fix contains a lot more than is needed for this specific issue, however the specific changes to django/db/backends/mysql/validation.py would be great to have in Django 1.7.

This worked fine in < Django 1.7 and works fine in upstream."	Bug	closed	Core (System checks)	1.7	Release blocker	fixed	mysql db_type		Accepted	1	0	0	0	0	0